Means and apparatus for molding hollow articles.



.PATENTBD JUNE 16, 1903..

C. HUBER. MEANS AND APPARATUS FOR MOLDING HOLLOW ARTICLES.

APPLIUATION FILED AUG. 11, 1902.

N0 MODEL.

W629i 6136 as,

I No. 731,367,

UNITED STATES Patented June 16, 1903.

PATENT rFIcE,

OARL HUBER, OF KARLSRUHE, GERMANY, ASSIGNOR TO GESELLSCHAFT FUR HUBERPRESSUNG GESELLSOHAFT MIT BESCHRANKTER I'IAFTUNG OF KARLSRUH E, OF BADEN, GERMANY.

MEANS AND APPARATUS FOR MOLDING HOLLOW ARTICLES.

SPECIFICATION forming part of Letters Patent No. 731,367, dated June 16, 1903.

Application filed August 11, 1902. Serial No. 119,332- (No model.)

To (Mfr/17mm, it may concern:

Be it known that I, CARL HUBER, a citizen of Germauy,residing at 38 BeiertheimerAllee,

Karlsr'uhe, Baden, Germany, have invented,

certain new and useful Improved Means and Apparatus for Molding I-Iollow Articles, (for which I have applied for a patent in Great Britain, dated January 16, 1902, No. 1,225,) of which the following is a specification.

This invention relates to the manufacture of hollow articles from a flat blank or plate by means of a flexible hollow pressing device filled with liquid, which I will term a watercushion and which is so arranged and operated that it serves both as a drawing-tool for drawing the flat blank into a mold and also as the pressing-tool for pressing the drawn object into the required shape.

I will describe the apparatus which I employ for the purpose of my invention with reference to the accompanying drawing, which represents a vertical section of the same.

The mold or matrix m for the hollow article to be produced,which is preferably formed of four separate parts, is contained in a coned .outer casing upon which is laid the sheetmetal blank or plate I). This is held down upon the mold by a tubular holding device 01, which is provided with an annular watercushion 76, adapted to press upon the sheetmetal blank, while the plunger 19, with its water-cushion w, effects the drawing operation.

The plungerp, which is subject to the pres- I sure of the platen a of a hydraulic or other press, is of tubular form, so as to receive within it the tubular extension 10 of the water-cushion to, which forms a flexible continuation of the plunger 12. The tubular extension w is open at the upper end for enabling the cushion w to be filled with liquid, the upper end of the plunger-bore being closed by a screw-plug c after the filling has been effected. I

The holding device at is movably connected to the upper flanged end of the plunger 13 by bolts cl, on which are mounted helical springs f, whereby the downward pressure exerted by the platen a upon the plunger 19 is transmitted in a yielding manner to the holder '12,

descent of the platen the springs f cause the holder n to project with its lower end somewhat below the lower end of the water-cushion 111, so that as the platen and plunger descend the cushion 7c of the holder is first made to bear upon the blank I so as to hold it before the plunger 1) and water-cushion to begin todrawthe central part of the blank into the mold. When by thisoperation the bottom of the cushion w is brought to bear againstthe bottom of the mold m, with the interposition of part of the drawn blank, then on the'continuation of the downward motion of the plunger the increasing pressure transmitted to ,all parts of the confined body of water in the cushion 20 will cause this to be bulged out laterally, whereby the drawn blank 11 will be expanded in a corresponding manner, so as to assume the configuration of the mold m and of any ornamentation that may exist thereon. On the completion of the molding operation the plunger 19, together with the water-cushion w and holder n, are drawn upward again, so as to allow the molded hollow article to be removed from the mold.

The flexible water-cushion to can either be made of caoutchouc or of leather or other suitable flexible material that will withstand the required pressure. When the apparatus is employed for molding articles out of a blank of celluloid or other material-such as pulverulenthorn, marble, and the like-that requires heat combined with pressure for molding and consolidating it the water-cushion is heated by filling it with hot water or other suitable hot liquid.

Having thus described the nature of this invention and the best means I know of carrying the same into practical effect, I claim 1. Apparatus for molding hollow articles from a flat blank consisting of the combination of a plunger, a flexible receptacle filled with liquid carried by said plunger, and a the arrangement being such that before the tubularholding-down device surroundingthe lower part of the plunger with the flexible receptacle and adapted to hold a flat blank upon upon the edges of the blank while the plunger and water-cushion effect the drawing and molding of the central part thereof, substantially as descri bed.

3. An apparatus for molding hollow articles from a flat blank, comprising the combination with aplunger and mold, of a flexible receptacle containing a liquid and adapted to 0perate as a tool for drawing the blank into the mold and then acting as an expanding molding-tool for causing the drawn blank to assume the configuration of the mold, and means for suitably holding the blank upon a mold for the purpose set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

CARL HUBER.

Witnesses:

HENRY HASPER, WoLDEMAR HAUPT. 

